The UN Envoy to Yemen, Martin Griffiths, arrived here on Wednesday and headed along with his delegation to downtown in capital Sanaa.
But he made no statements to reporters upon his arrival, Xinhua news agency reported.
On Friday, Griffiths told the UN Security Council that he planned to visit the embattled port city of Hodeidah. He urged the Council to adopt a humanitarian truce before holding peace talks in Sweden within weeks.
A round of talks in Geneva collapsed in September after the Houthi delegation did not attend.
Yemen has been in a civil war in the past three years, pitting Houthi rebels and forces loyal to the government of Abd-Rabbuh Mansur Hadi.
Saudi Arabia leads an Arab military coalition to support the Hadi government.
Houthi rebels have announced an halt to launching missiles at Saudi Arabia and the United Arab Emirates.